net: ethernet: davinci_emac: Fix Unbalanced pm_runtime_enable

net: ethernet: davinci_emac: Fix Unbalanced pm_runtime_enable

In order to avoid an Unbalanced pm_runtime_enable in the DaVinci
emac driver when the device is removed and re-probed, and a
pm_runtime_disable() call in davinci_emac_remove().

Actually, using unbind/bind on a TI DM8168 SoC gives :
$ echo 4a120000.ethernet > /sys/bus/platform/drivers/davinci_emac/unbind
net eth1: DaVinci EMAC: davinci_emac_remove()
$ echo 4a120000.ethernet > /sys/bus/platform/drivers/davinci_emac/bind
davinci_emac 4a120000.ethernet: Unbalanced pm_runtime_enable

Cc: Brian Hutchinson <b.hutchman@gmail.com>
Fixes: 3ba97381343b ("net: ethernet: davinci_emac: add pm_runtime support")
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: David S. Miller <davem@davemloft.net>